Vote splitting

This construct has long been a feature of Approval Voting advocacy. It refers to the possibility that two or more likeminded candidates in a plurality election appeal to the same group of voters, thereby dividing that group’s support.

Advocates of Approval Voting (and derivative rules) naturally gravitate to this construct. It is intuitive. It seems like it happens often. And, on its face, it makes a great case for Approval Voting. Heck, you just vote for both candidates!

With the entry of “vote splitting” into high-profile RCV advocacy, it may be time to take a critical view.

Nagel has shown that, under Approval Voting, two candidates appealing to the same group of voters actually have an incentive to encourage vote-splitting. The reason is that each cares about winning.

I am told of similar results for the Alternative Vote (aka IRV/RCV).

What about vote-splitting where everyone thinks it happened? I am talking about prominent presidential elections with minor-party candidates. Two recent studies suggest relatively little vote-splitting in practice: one on Libertarians, then a second on Stein/Greens and Johnson/Libertarians alike.

To find that third-party voters don’t break reliably in either direction is not surprising. Typically, such candidacies reflect the activation of some alternative issue dimension (e.g., climate).

That issue may even be so important (to third-party voters) that they refuse to rank (or approve/score) putative lower choices. Hence the Australian solution: compulsory ranking.

My personal view is that “vote splitting” has become an indulgent kludge. The obvious solution to the purported problem is to unite behind a single candidate. But this just will not do for a certain kind of reformer (indulgent). And it is a kludge because the problem is not demonstrated (nay, demonstrable) empirically — at least without considerable data on the policy preferences of voters and candidates alike.

Yet we will continue to hear about “vote splitting” because, without it, the case for single-seat reform evaporates.

Reform measures in November 2018

Just a short note about Election Day referenda on alternative voting systems. I have been too busy to follow developments closely. The British Columbia vote on proportional representation is interesting to watch, however. All the old arguments are coming back out, which is what you could expect here, should we ever see another PR vote in a city or state with party competition. Anyway…

MEMPHIS (TN): Population 652,236. Voters are asked to repeal a never-implemented system of instant runoff (single-winner ranked-choice) voting. Actress Jennifer Lawrence has urged a “no” vote, working with Represent.US. (She and Represent.US also campaigned for RCV’s retention in Maine.) If implemented, RCV would replace a delayed-runoff system with majority threshold. Voters adopted RCV in 2008 (71 percent in favor). The local reform group, Save IRV Memphis, notes a large drop-off in some wards between the October first round and November runoff. The group says this drop-off is correlated with poverty.

FARGO (ND): Population 122,359. Voters will decide whether to switch to approval voting. Under this rule, voters check off any candidates of which they “approve,” and winners are those with the most votes. Elections to Fargo’s city commission are at large, by plurality, in a four-seat district two districts of two seats each. Backing the measure is the Center for Election Science, recently funded by the Open Philanthropy Project. A CES poll has support at 43 percent (with 36 percent saying “don’t know”). Prof. Mark Johnson of Minnesota State Community and Technical College weighs in. If passed, this would be the first adoption of approval voting for public elections in the US.

LANE COUNTY (OR): Population 369,519. Voters will decide whether to switch to STAR (“Score Then Automatic Runoff”) voting. With STAR, voters rate candidates on a 0-5 scale. Two candidates proceed to a runoff — those with the two highest sums of scores. In the runoff, each ballot counts toward the highest-scored candidate on it. (Ballots without most-preferred candidates do not continue to the runoff — they “exhaust.”) Lane County’s five-member Board of Commissioners is elected in a non-partisan, top-two system to five numbered posts. Backing the measure are STAR Voting for Lane County and the Equal Vote Coalition. STAR was invented in 2014. Organizers secured 16,000 signatures. Alan Zundel (formerly of UNLV) weighs in.

Sorry if I missed any. Let me know by the usual channels.